Catalytic dehydrogenation of secondary alcohols to ketones



Patented Mar. 31, 1953 CATALYTIC DEHYDROGENATION 0F SEC- onDARY ALooHoLs- T0 KETONES Henry 0. Mottern, Bloomfield, N. J assignor to Standard Oil Developme ration of Delaware nt Company, a corpo- No Drawing. Application January 11), 1950,

Serial No. 137,903

8 Claims.

This invention relates to a novel catalyst carrier, particularly a carrier for metallic oxide dehydrogenation catalysts. Specifically, the invention is concerned with a novel dehydrogenation catalyst comprising at least one metallic oxide on a fused zirconia base.

Numerous chemical reactions are carried out in the presence of catalysts which require deposition on catalyst supports. For example, the dehydrogenation of secondary alcohols to ketones is commonly accomplished by passing alcohol vapors at elevated temperatures over a catalytic metallic oxide supported on a carrier. Generally oxides of the metals of group II of the periodic table are employed with the addition thereto of metallic oxides of group IV and/or group V as catalyst promoters, stabilizers, etc. For purposes of this invention the term metallic oxide dehydrogenation catalyst will designate an oxide of a metal, preferably of group II, and 1 to 15% by Weight of a metallic oxide of the Il'Ird, IVth, and Vth group of the periodic table. During the dehydrogenation temperatures of 400 F. to 1000 F., generally 750 F. to 900 F. are employed. The catalytic metallic oxides function with a higher degree of efficiency when supported on a carrier than when used alone. Catalyst carriers commonly used are metallic machine turnings such as steel or brass turnings, metallic chips, pumice, alumina, porcelains, etc. of a size insuring good distribution of the oxide throughout the catalyst chamber. Metallic carriers have been aiforded wide use commercially as a convenient, easily replaceable support.

It has been found that relatively large size lumps of fused zirconia, which in itself is relatively catalytically inactive, is an excellent support for metallic oxide catalysts. It is considerably cheaper than metallic carriers, and catalysts coated thereon display longer stability and afford higher conversions than the same catalyst deposited on metallic carriers.

Fused zirconia is available as a by;-product from the distillation of zirconia sands. The electrically fused zirconia mass can. be broken into lumps of appropriate size-for various uses. For purposes of this invention lumps or granules varying from the general size of 4" cube to a cube, preferably about /2" cube, are desirable. These granules are hard, non-porous, ir-

regular in shape, salmon to gray in color and have a porcelain-like finish. Quite unexpectedly the material is extremely stable when put through cycles of alternate heating and cooling. No signs of any appreciable crazing, cracking or disintegration occurs despite repeated washings, re-coatings and re-use.

The catalyst is applied to the carrier by forming a, slurry of the metallic oxide or oxides with Water or other solvent until a paste-like consistency is obtained. The fused zirconiain the form of lumps .or granules of the'apprcpriate size, preferably about /2" x /2 x is mixed with the oxide paste and the oxide deposited thereon by known methods such as by tumbling in a ball mill. During the tumbling operation the, oxide becomes deposited on the fused zircoma-leaving the exterior surface of the mass relatively smooth. The particles are-removed and dried, and are then ready for use in the reactor.

Although the fused zirconia is an excellent catalyst carrier in itself, it has been found that even still better results are obtained if the fused zirconia is treated before use in'the catalyst com;

positionwith an aqueous solution of analkali such as sodium hydroxide, potassium hydroxide or ammonium hydroxide, preferably the latter. When the fused zirconiais preliminarily digested with aqueous alkali preferably at its boiling point for a period of 5 minutes to 2 hours, theresult ing catalyst contained on the fused zirconia'car-j rier produces a minimum of olefin formation in the conversion of secondary alcohols to ketones,

' and results in longer life of the catalyst.

The metallic oxides preferably employed in the, dehydrogenation catalyst are selected from the following group: zinc oxide, magnesium oxide, copper oxide, beryllium oxide, chromium oxide; while the following oxides are employed as sta bilizers and promoters where desired: bismuth oxide, antimonyoxide', zirconium oxide, thorium oxide, cerium oxide, vanadium .oxide, etc. The amount of the latter oxides used varies between 1 and 15 wt. per cent, preferably about ,6 wt. per. cent based on the total weight of the mixture. J

The following dehydrogenation runs in Table -I demonstrate the effectiveness of the fused zir-= coma-base catalyst. The parts of the oxides employed as given are parts by weight.

Table I DEHYDROGENATION OF ISOPROPANOL ACE'IONE M01. Percent Conversion to- Run No. Catalyst Carrier 222 5 3 Acetone IPOH Prw 94Zn0, 6Bi2O; Fused Zirconia 1.5 750 90.15 5.38 2 2 2. 2 942110, 6ZTOg d 1v 750 90.92 6. 5 1.47 1. l 94Zn0, 6BiiO3 .....d0 1.5 750 90. 8 6. 6 0. 93 1. 7

(Treated WJlIh..NH4QH) 942110, GZXOL- Fused Zirconia 1 5 750' 86.97 9. 77 2. 97 2. 3 94ZnO, GZrO. 6 O 750 68. 24 30. 23 0. 76 0. 7 94ZI10, 6Z1O 3 0 900 92.61 2. 77 2. 51 2. 1 94ZHO, 6Z1Oz- 1 5 750 90. 92 6. 5 l. 47 1. 1

DEHYDROGENATION OF} SECBUIIANOL METHYL ETHYL KE'IONE M01. Percent Conversion to Run No. Catalyst Carrier 1 MEK sec-BuOH Bu- L-fi 94Zn0, SBi2Os Fused Zirconia. 1. 5 750 g 2 4 5 94ZI10, r mnde 5 750. 83,1; 14, 0 6 942110, fiBlzQz..-- .do 1. 5* 750 31 06 3'2 (Treated with 5% NeQH) 1. 5 750 5 5 4 lMZnO, 6Zr.0 z Fusedzircoma.. 1.5 750 91 (i9 (Treated With-5% NaQH) 94Zn0, 6ZrOz.. Fused Z1rcon1a.. 1.5 750 95. l) 2. 2 1.6 i 1. 2

(Treated with NHiQH) 'Zr02 fused None 1.5 750- 3 8L5 44 .ZnO Fused.Z.1rc0nia.-- 1. 5 750 3 8, 95 8 88 The efiectiveness of thefused zirconia base in minimizing olefin formation during the. dehydrogenation of secondary alcohols is shown by the data in Table-IIwherein comparisonis made with steel and brass carriers. In all cases: the fused zirconia carrier with the same catalyst and undercomparable conditions, converted. less alcohol to olefin than either the steel or brass carrier.

Although. the effectiveness of the fused zirconia asa catalyst base has been demonstrated by, the. dehydrogenation of secondary alcohols to ketones, its. use is. byrn means limited thereto. The fused zirccnia issuitable as a base for metallic oxide catalysts which catalyze the dehydrogenation of primary alcohols to their corresponding aldehydes, e. g. the dehydrogenation of ethyl alcohol to acetaldehyde. The material likewise is suitable-for use in the dehydrogenation of hydrocarbons to produce hydrocarbons of greater unsaturation, e. g. the conversion of para-bins to mono-olefins and mono-olefins to diolefins.

The dehydrogenation is carried: out in theusual manner already described in the artand the use of the fused zirconia asthe catalystbase requires RO-mOCllfiCatlOIlS of the reaotion.,mechanism-, or, method of product recovery, etc. For example. the reaction conditions and process technique employed in the dehydrogenation of secondary alcohols'to ketones-are well described in the art, e..g. U. S. 2,039,543, 2393,516, 2 ,436,733, 2,436,970, etc. and are illustrated in thepreferred manner by the runs set forth in Table I oithespecifioation.

What is, claimed is:

1. Aprocess for converting secondary aliphatic alcohols to ketones which comprises passing the alcohol in the vapor phase under oonyersioilcon: ditions of temperature and pressure-over a cat:- alyst comprisin a group II ,metal oxide. coated on lumps of fused zirconia obtained'fromthe distillation of 'zirconia sands.

2. A process for converting secondaryallphatic alcohols to ketones which comprises passing the alcohol in the vapor phaseunder conversion conditions of temperature and pressure over a catalyst comprising a group II metal oxide coated on alkali-treatedlumps of fusedzirconia obtained from the distillation of zirconiasands.

'3. Aprocess for. converting-secondary aliphatic alcohols to ketones which comprises passing the alcohol in the vaporphase under conversion conditions of temperature and pressure over a catalyst comprising zinc oxide and 1-15% by weight based, on. the total weight of the catalyst of a promoter selected from the group consisting of oxides of. the metals of groups IV and V'of-the periodic system coatedon lumps of fused zirconia obtainedfrom the distillation of zirconia sands.

4. A, process for convertingsecondary aliphatic alcohols to ketones which comprises passing'the alcohol in the vapor phase. under conversion conditions of temperature and, pressure over a.v catalyst comprising zinc oxide and 1-15% by weight based on the total weight of the catalyst of a promoter selectedfrom, the group consisting. of oxides of the metals of groupsIV and. V. of. the periodic system coatedon alkalirtreated lumpsof fused zirconia obtained from the. distillation of zirconia sands.

5.. A processfor converting secondary aliphatic. alcohols to .ketones which comprises passing the alcohol in the vapor phase. under conversion conditions of temperature and pressure over. a cat.- alyst comprising zinc oxide and 1 to 15% by weightof the total oxides of bismuth oxide-coated on lumps of fused zirconia obtained from the distillation of zirccnia sands.

6. A process for converting secondary aliphatic alcohols to ketones which comprises passing the alcohol in the vapor phase under conversion conditions of temperature and pressure over a catalyst comprising zinc oxide and 1 to 15% by weight of the total oxides of bismuth oxide coated on alkali-treated lumps of fused zirconia obtained from the distillation of zirconia sands.

7. A process according to claim 5 in which isopropanol is converted to acetone.

8. A process according to claim 5 in which secondary butanol is converted to methyl ethyl ketone.

HENRY O. MOTIERN.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Taylor Jan. 5, 1937 Fuchs Sept. 7, 1937 Huppke Apr. 7, 1942 Huppke Apr. 7, 1942 Kirkpatrick Oct. 19, 1943 Schneider et al Feb. 24, 1948 Mistretta Mar. 2, 1948 Schneider et a1 June 7, 1949 Nahin Nov. 8, 1949 Fleck Mar. 14, 1950 FOREIGN PATENTS Country Date Great Britain Nov. 6, 1930 

1. A PROCESS FOR CONVERTING SECONDARY ALIPHATIC ALCOHOLS TO KETONES WHICH COMPRISES PASSING THE ALCOHOL IN THE VAPOR PHASE UNDER CONVERSION CONDITIONS OF TEMPERATURE AND PRESSURE OVER A CATALYST COMPRISING A GROUP II METAL OXIDE COATED ON LUMPS OF FUSED ZIRCONIA OBTAINED FROM THE DISTILLATION OF ZIRCONIA SANDS. 